Safety device for motor cars



4 1927. Oct G. E. LYNCH SAFETY DEVICE FOR MOTOR CARS Filed Aug. 14. 1922 LLP Patented Oct. 4, 1927. i

UNITED STATES GEORGE E. LYNCH, OF LOS ANGELES, CALIFORNIA.

SAFETY DEVICE FOR MOTOR CARS.

Application led August 14, 1922. Serial No. 581,351.

The principal yobject of my invention is to promote the safety of automobile and truck driving by confining the movement of v the vehicle to the direction determined .by the setting of the gear lever. It is appllcable to all classes of engine or motor driven vehicles using the spur gear type of transmission.

My invention is based on the fact that in all transmissions of the spur gear type, certain shafts and gears rotate invariably in the same direction under all normal movements of the bar. This includes the clutch gear and its shaft, the countershaft and gears, and the reverse idler. The only time that any member of this train reverses its direction of rotation is when the car is moving backward while 4in forward gear, or forward while in reverse gear. Neither of these movements is at any time necessary or advantageous and either one may readily be the cause of serious accident, especially on Vsteep grades.

My` invention provides locking means between the clutch and the splined shaft, or propeller shaft, and it may be applied to the clutch gear,l the countershaft, or the reverse idler, according to the convenience of installation in any given type of transmission of the spur gear type. With an unskilled or nervous driver, or possibly with a skilled driver, the killing of an engine on a grade sometimes allows the car to run backward and to go over a bank or the like before the driver can apply his brakes. To start the car under such conditions requires great skill and many manipulations. With my invention interposed in the manner indicated, it acts automatically and does not interfere with the starting'of the car when stopped, any more than does a block placed under the rearwheels of a car headed upgrade.

In order to .clearly explain my invention, I have illustrated the samel on the accompanying sheet of drawings in which,-

Figure l is a vertical sectional view through a transmission mechanism in which Y my invention is embodied;

Figure 2 is a cross sectional View taken on line 2 2 of Fig. 1; 4

Figure 3 is a sectional view taken on line 3-'-3 Of'Fig. 1;

Figure 4 is a sectional view taken on line 4 4 of Fig. 3;

Figure 5 is a view of a slightly modified form of my invention; and v F Figure 6 is a sectional view through said Referring more in detail to the drawings, my lnvention'as here illustrated for descriptive purposes, comprises in combination with a spur gear transmission, designated as a whole A, a ratchet mechanism, as shown in Figs. 3 and 4, or as shown in Figs. 5 and 6. In Figs. 3 and 4, I have shown a ratchet mechanism comprising an outer ring 10a, with a plurality of pawls, 10b, pivotally mounted therein, and springs l()c for normally moving said pawls inwardly against the inner notched ring 10d, mounted on the reverse idler shaft, 12, of the transmission mechanism. The notched ring, or hub-like member 10, is shown as an extension of the hub portion of the reverse idler gear 10e. The pawls 10b are shown of substantial width, as will be clear in Fig. 4. In Figs. 5 and, I have shown a roller ratchet mechamsm, 11, an outer ring, lla, being provided with eccentrically .disposed runways, 11b, in which are placed rollers, 11C, which run on the periphery of a hub-like extension of the reverse idler gear 12, said hub-like'extension being designated 11d. No matter which form of ratchet mechanism is used, they both function inthe same manner. Ratchets in and of themselves, of course are old, just as are the gears and shafts, and my invention lies in the particular combination and its new arrangement whereby a simple safety device is made a part of the transmission mechanism without any important changes therein, and being located in a high speed portion of the driving mechanism of the car, may be comparatively small and light.

In the drawings, G, designates the low speed gear on the counter-shaft in a standard transmission; J designates the sliding gear which, when in mesh with gear G, gives low speed forward and when in mesh with gear 10e, gives reverse movement; and I-I designates a pinion on the counter shaft which is constantly in mesh with vgear 10e, which is the reverse idler. i

This constitutes the usual and well known selective type of transmission which includes a plurality of gear pairs of different ratios mounted on parallel shafts, one of which is driven from the source `of power, with means consisting Iof sliding the gears, engaging and disengaging clutches, or moving keys, whereby only one of these pairs of gears may bein engagement at any given time. This is so common that further description thereof need not be given here. In

all such gear mechanisms, the drive is from.

a gasoline engine which rotates linvariably in one directionwhen delivering power, and

trar f 'l shag wheels.

reverse of the direction of movement of the car requires the provision of a third, or idler gear, called the reverse idler'to give a con- Adirection of rotation to the propeller which transmits the power to the rear This involves as a necessity that certaingears and shafts in the transmission rotate invariably in one directionin all normal movements of the car. These gears f and lshafts comprise the clutch gear the countershaft and the reverse idler, an vare known usually and collectively as the .con-v stant gear train. The object of my invention is the provision of a simple locking device to prevent reverse rotation, Aat all times, of .all the members of this train.

In many transmissions the idler .gear 10e already has the hub-like` extension 10d to Aserve as' a spacing means, and I utilize this forone part of the ratchet mechanism which I embody in the transmission 'mechanism.V

For 'the outer member of the ratchet, I provide the outer'ringor member 10, and provide at'one side thereof ali extension 10c which fits overl the end of the countershaft 13, by which said outer-.ring member of the. ratchet is held from turnin Thus I am able to provide in a space w ich is already available without reconstruction, a simple and practical means for preventing backward movement of an automobile in case `the engine is stopped while the gears are set for forward drive and accomphsh it in a com paratively inexpensive manner.

The use and 'operation of my invention as herein illustrated, may be briefly described as follows: t

The notched ring 10", on the reverse idler shaft 12,1'is'surrounded by the outer ring 10,

having the pawls, 10", pivotally mounted therein and engaging with said notched ring, w1th the extension 1()x connected with the nend of the' countershaft 131 vThe reverse' u' idler is, therefore, free to turn in vone direction but will be held against turning inthe opposite direction by the pawls 10" engaging with the notched ring 10". Inasmuch as the reverse idler shaft must always turn in one direction when the transmission is set for f normal movement, either forwardly or backwardly, it will be clear that the machine cannot be moved forwardly when set in re- 1i versegear, or rearwardly when set in for- Lacasse 'shift is set for'reverse moyement. vNeither movement is every necessary or advantageous and either of such movements maybe tho causeof an accident when the vehicle is.

starting on a grade. My device operates when any such unnecessary movement starts by reason of the fact that the pawls at once lock thereverse idler and the entire gear train against such rotation. The operation of this device renders the control sitive by limiting the movement of the vehicle absolutely to the direction determined by the setting of the gear shift lever. On account of. the great ratio between the reverse idler and the rearnwheels, the rotation lof the notched ring 10d at allA ordinary speeds ofthe car is sufficient to hold the pawls 10" out of engagement and there is not suilicient time for them to be moved inwardly between two passing notches, thus avoiding all noise.-

Of course it is old to `provide ratchet Y,

mechanism for preventing reverse rotation and I do notl claim this, and I do not claim to be the first to undertake toprevent the backward movement ofan automobile under the conditions mentioned, but, so far as I am luc aware, I am the first to provide an inter` `v locking means interposed between the clutch and the propeller or drive shaft which operates automatically to prevent such backward movement. I do not, therefore, limit my invention to the details shown 'for illustrative purposes exce tas I may be limited'bythehereto appen ed claims.

I claim: .1. In a motor vehicle, in ycombination with theI transmission gears, idler shaft, counter shaft and gears thereon, of a fixed ratchet. element` around one of .said 4shafts with means extending to the other shaft for holding it, a revolving ratchet element on said first mentioned shaft `within saidv fixed ratchet element, and interlocking ratchet means between said fixed and revolvin ratchet elements andl adapted to prevent sai velements from turning contrary tothe di-l rection for which the are set to turn.

2. In a motor vehic e and the transmission mechanism thereof, a fixed ratchet element through which two shafts of the transmis# sion'l mechanism pass, \a revolving ratchet element on one of said shafts, within said fixed ratchet element, and interlocking vratchet elements interposed between said @fixed and said revolving ratchet elements.

3. In a motor vehicle, in combination with `idler shaft and the counter shaft of the transmission mechanism, of a non-rotatable ratchet element around both Shafts, and a 5 revoluble ratchet element on one of sai shafts within said nonrotatable ratchet element, and interlocking means between said ratchet elements arranged to prevent said elements from turning contrary to the direction for which they are setto turn.

Signed at Los Angeles, Los Angeles d County, California, this 9th day of-August,

GEORGE E. LYNCH 

